1 files changed, 117 insertions, 0 deletions
diff --git a/services/common/blocklist-updater.js b/services/common/blocklist-updater.js
new file mode 100644
index 000000000..3b39b9552
--- /dev/null
+++ b/services/common/blocklist-updater.js
@@ -0,0 +1,117 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+this.EXPORTED_SYMBOLS = ["checkVersions", "addTestBlocklistClient"];
+
+const { classes: Cc, Constructor: CC, interfaces: Ci, utils: Cu } = Components;
+
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/Task.jsm");
+Cu.importGlobalProperties(['fetch']);
+const BlocklistClients = Cu.import("resource://services-common/blocklist-clients.js", {});
+
+const PREF_SETTINGS_SERVER              = "services.settings.server";
+const PREF_BLOCKLIST_CHANGES_PATH       = "services.blocklist.changes.path";
+const PREF_BLOCKLIST_BUCKET             = "services.blocklist.bucket";
+const PREF_BLOCKLIST_LAST_UPDATE        = "services.blocklist.last_update_seconds";
+const PREF_BLOCKLIST_LAST_ETAG          = "services.blocklist.last_etag";
+const PREF_BLOCKLIST_CLOCK_SKEW_SECONDS = "services.blocklist.clock_skew_seconds";
+
+
+const gBlocklistClients = {
+  [BlocklistClients.OneCRLBlocklistClient.collectionName]: BlocklistClients.OneCRLBlocklistClient,
+  [BlocklistClients.AddonBlocklistClient.collectionName]: BlocklistClients.AddonBlocklistClient,
+  [BlocklistClients.GfxBlocklistClient.collectionName]: BlocklistClients.GfxBlocklistClient,
+  [BlocklistClients.PluginBlocklistClient.collectionName]: BlocklistClients.PluginBlocklistClient
+};
+
+// Add a blocklist client for testing purposes. Do not use for any other purpose
+this.addTestBlocklistClient = (name, client) => { gBlocklistClients[name] = client; }
+
+// This is called by the ping mechanism.
+// returns a promise that rejects if something goes wrong
+this.checkVersions = function() {
+  return Task.spawn(function* syncClients() {
+    // Fetch a versionInfo object that looks like:
+    // {"data":[
+    //   {
+    //     "host":"kinto-ota.dev.mozaws.net",
+    //     "last_modified":1450717104423,
+    //     "bucket":"blocklists",
+    //     "collection":"certificates"
+    //    }]}
+    // Right now, we only use the collection name and the last modified info
+    let kintoBase = Services.prefs.getCharPref(PREF_SETTINGS_SERVER);
+    let changesEndpoint = kintoBase + Services.prefs.getCharPref(PREF_BLOCKLIST_CHANGES_PATH);
+    let blocklistsBucket = Services.prefs.getCharPref(PREF_BLOCKLIST_BUCKET);
+
+    // Use ETag to obtain a `304 Not modified` when no change occurred.
+    const headers = {};
+    if (Services.prefs.prefHasUserValue(PREF_BLOCKLIST_LAST_ETAG)) {
+      const lastEtag = Services.prefs.getCharPref(PREF_BLOCKLIST_LAST_ETAG);
+      if (lastEtag) {
+        headers["If-None-Match"] = lastEtag;
+      }
+    }
+
+    let response = yield fetch(changesEndpoint, {headers});
+
+    let versionInfo;
+    // No changes since last time. Go on with empty list of changes.
+    if (response.status == 304) {
+      versionInfo = {data: []};
+    } else {
+      versionInfo = yield response.json();
+    }
+
+    // If the server is failing, the JSON response might not contain the
+    // expected data (e.g. error response - Bug 1259145)
+    if (!versionInfo.hasOwnProperty("data")) {
+      throw new Error("Polling for changes failed.");
+    }
+
+    // Record new update time and the difference between local and server time
+    let serverTimeMillis = Date.parse(response.headers.get("Date"));
+
+    // negative clockDifference means local time is behind server time
+    // by the absolute of that value in seconds (positive means it's ahead)
+    let clockDifference = Math.floor((Date.now() - serverTimeMillis) / 1000);
+    Services.prefs.setIntPref(PREF_BLOCKLIST_CLOCK_SKEW_SECONDS, clockDifference);
+    Services.prefs.setIntPref(PREF_BLOCKLIST_LAST_UPDATE, serverTimeMillis / 1000);
+
+    let firstError;
+    for (let collectionInfo of versionInfo.data) {
+      // Skip changes that don't concern configured blocklist bucket.
+      if (collectionInfo.bucket != blocklistsBucket) {
+        continue;
+      }
+
+      let collection = collectionInfo.collection;
+      let client = gBlocklistClients[collection];
+      if (client && client.maybeSync) {
+        let lastModified = 0;
+        if (collectionInfo.last_modified) {
+          lastModified = collectionInfo.last_modified;
+        }
+        try {
+          yield client.maybeSync(lastModified, serverTimeMillis);
+        } catch (e) {
+          if (!firstError) {
+            firstError = e;
+          }
+        }
+      }
+    }
+    if (firstError) {
+      // cause the promise to reject by throwing the first observed error
+      throw firstError;
+    }
+
+    // Save current Etag for next poll.
+    if (response.headers.has("ETag")) {
+      const currentEtag = response.headers.get("ETag");
+      Services.prefs.setCharPref(PREF_BLOCKLIST_LAST_ETAG, currentEtag);
+    }
+  });
+};